DPDT Relay for Motor Direction Control

Question

Problem: DPDT Relay for Motor Direction Control. Solve this hands-on electronics task on EWskills.

Accepted Answer

1. Component Purpose

To reverse a DC motor’s direction, you need to reverse the polarity of the voltage applied to it. A DPDT (Double Pole, Double Throw) relay has two sets of changeover contacts that can swap the motor’s connections simultaneously.

When the relay is de-energized, the motor runs in one direction. When energized, both poles switch together, reversing the motor’s polarity and spinning it the opposite way.

Required: General Purpose · 12VDC coil · DPDT (2 Form C) · ≥5A contacts · 12VDC rated · Non Latching · Through Hole

2. How to Find It on DigiKey

Go to DigiKey.com → Relays → General Purpose Relays

Apply these filters:

Coil Voltage → 12VDC
Contact Form → DPDT (2 Form C)
Contact Rating (Current) → 5A or higher
Coil Type → Non Latching
Mounting Type → Through Hole
Part Status → Active

Important: DPDT is not the same as 2x SPDT. A DPDT relay switches both poles simultaneously with a single coil — critical for safe motor polarity reversal. Using two separate SPDT relays risks a brief short if they don’t switch at exactly the same time.

3. Key Specifications & What They Mean

Specification	Required	Why
Coil Voltage	12VDC	Matches driver supply.
Contact Form	DPDT (2 Form C)	Two poles needed for polarity reversal.
Contact Current	≥5A	Motor draws 2A; margin for DC arc + inrush.
Switching Voltage	12VDC rated	Must be rated for DC switching.
Coil Type	Non Latching	Direction set by control signal state.
Mounting	Through Hole, PC Pin	Standard PCB mount.
Temp Range	−40°C to +85°C	Industrial conditions.
Safety Approval	cURus or equiv.	Product certification.

4. Selecting a Safe, Production-Ready Part

The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?

Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide

5. Filtered DigiKey Link

➡ View Matching Parts — 12VDC Coil, DPDT, ≥5A, Through Hole

57. DPDT Relay for Motor Direction Control